Optical universal serial bus (usb)

ABSTRACT

Embodiments of the invention are directed to an optical USB (OUSB) to enhance the data rate of USB by adding super-high data rate (e.g. 10 Gbps) optical communication on top of its current specification so that backward compatibility is achievable. Mechanical tolerances may be achieved by using embedded lenses to expand a beam emerging from the connector prior to entering its mating connector and using an identical lens in the mating connector to collimate the beam back onto a fiber.

PRIORITY

This application is a Continuation of and claims priority to U.S. patentapplication Ser. No. 11/731,810 filed Mar. 30, 2007.

FIELD OF THE INVENTION

Embodiments of the invention relate to the universal serial bus and,more particularly, to a USB including having optical capabilities.

BACKGROUND INFORMATION

In many of today's processing systems, such as personal computer (PC)systems, there exist universal serial bus (USB) ports for connectingvarious USB devices. Some of these USB devices are frequently used by PCusers. For example, these USB devices may be printers, compact diskread-only-memory (CD-ROM) drives, CD-ROM Writer (CDRW) drives, digitalversatile disk (DVD) drives, cameras, pointing devices (e.g., computermouse), keyboards, joy-sticks, hard-drives, speakers, etc. Some of thesedevices use more of the available USB bandwidth than others. Forexample, a USB CDRW is a high bandwidth device, while human interfacedevices (HID), such as computer mice, keyboards and joysticks, are lowbandwidth devices.

Within a USB cable there are typically four shielded wires. Two of thewires may provide power (+5 volts (red) and ground (brown)) and atwisted pair (blue and yellow) for data.

At either end of a USB cable there is a standard sized connector. Theseconnectors each has a different profile designated “A” connectors and“B” connectors. More recently, mini versions of these connectors areappearing to accommodate smaller devices. “A” connectors head “upstream”toward the computer. On the other end, “B” connectors head “downstream”and connect to individual devices. This way, it is almost fool proof tomake a wrong connection.

The USB standard allows for low power devices (e.g., mice, memorysticks, keyboards, etc.) to draw their power from their USB connection.Larger devices requiring more power, such as scanners or printers,typically have their own dedicated power supply.

FIG. 1 shows a typical USB “A” male connector 10. The cable 12,comprises the above mentioned four wires and connects to a plastichousing 14. Each of the four wires electrically connects within thehousing 14 to one of four contact terminals or pins 16 mounted on thetop side of an insulative base 18. The insulative base 18 is wrapped ina metal shield 19. Openings 20 in the metal shield may be provided tolock the connector in place when plugged into a corresponding femaleconnector.

FIG. 2 shows a more detailed view of the insulative base 18. As shown,conductive fasteners 21, 22, 23, and 24 are provided at one end toconnect to each of the four wires in the cable 12. The outer twofasteners 21 and 22, are for power and the inner two connectors 23 and24 are for data. On a top side of the insulative base 18 are four pins31, 32, 33, and 34, corresponding to the contacts 21, 22, 23, and 24,respectively. The pins 31-34 within the male connector 10 electricallyengage to mating pins within the female connector when plugged in.

Different standards of USB technology have different bandwidths. Forinstance, Universal Serial Bus Specification, revision 1.1, Sep. 23,1998 (USB 1.1) devices are capable of operating at 12 Mbits/second(Mbps). Universal Serial Bus Specification, revision 2.0, Apr. 27, 2000(USB 2.0; also known as high-speed USB) devices are capable of operatingat 480 Mbps. However, as technology progresses engineers are constantlystriving to increase operating speeds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a typical USB “A” male connector;

FIG. 2 is a block diagram showing a more detailed view of the insulativebase of a USB “A” male connector;

FIG. 3 is a top view of an insulative base of a USB “A” male connectoraccording to embodiments of the invention;

FIG. 4 is a bottom view of an insulative base of a USB “A” maleconnector according to embodiments of the invention;

FIG. 5 is a block diagram of a female USB “A” connector according toembodiments of the invention; and

FIG. 6 is a cross sectional view of a mated USB “A” connector accordingto embodiments of the invention.

DETAILED DESCRIPTION

Embodiments of the invention are directed to an optical USB (called OUSBhereafter) to enhance the data rate of USB by adding super-high datarate (e.g. 10 Gbps) optical communication on top of its currentspecification so that backward compatibility is achievable.

A challenge with OUSB is the need to be backward compatible with thelegacy USB form factor, which requires relatively large mechanicaltolerances. That is, the mechanical tolerance specified by the USBconnector is 0.3 mm. Optical connectors typically use a butt contactapproach. However, optical butt contact may require 10 um precision orbetter. This makes the usual optical connector an unviable solution forUSB form factor.

In order to resolve this issue, embodiments disclose an optical beamexpanding approach. By expanding the beam size to, for example, 1 mm,the 0.3 mm mechanical tolerance required by the USB connector may beachieved.

Referring now to FIGS. 3 and 4, there is shown a top view and a bottomview, respectively, of the insulative base 18 of an OUSB connectoraccording to one embodiment of the invention. Similar to that which isshown and described in FIG. 2, conductive fasteners 21, 22, 23, and 24are provided at one end to connect to each of the four wires in thecable 12. The outer two fasteners 21 and 22, are for power and the innertwo connectors 23 and 24 are for data. On a top side of the insulativebase 18 are four pins 31, 32, 33, and 34, corresponding to the contacts21, 22, 23, and 24, respectively. The pins 31-34 within the maleconnector 10 electrically engage to mating pins within the femaleconnector when plugged in.

In addition, the OUSB connector comprises embedded lenses 40, 41, 42,and 43 on the leading edge of the insulative base 18. These lenses areoptically coupled to respective fibers 50, 51, 52, and 53 for providinghigh speed optical data throughput. While four lenses are shown, this isby way of example and more or fewer may be provided. The lenses 40-43may be within tapered holes as shown for fiber self-alignment ininstallation. The tapered holes may have metal inserts for addedrigidity. While not shown in FIGS. 3 and 4, the insulative base 18 wouldbe contained in a plastic housing 14 and include a metal shield 19 asshown in FIG. 1.

FIG. 5 shows the inside of an “A” connector female OUSB configured tomate with the connector shown in FIGS. 3 and 4. As in standard USB, aninsulative carrier 50 may comprise four contacts 51, 52, 53, and 54,which may be spring loaded, adapted to make electrical connection withpins 31, 32, 33, and 34, respectively, in the male connector. The fourcontacts 51, 52, 53, and 54 may be in turn electrically connected to aUSB device with contact posts 61, 62, 63, and 64. Four fibers 70, 71,72, and 73 may enter the female connector and be optically coupled tofour embedded lenses 80, 81, 82, and 83, which, when connected,optically couple to the corresponding lenses 40-43 in the maleconnector.

FIG. 6 shows a cut-away side view of a male OUSB connector 88 and femaleOUSB connector 90 when mated. For simplicity, the electrical connectionsare not shown in this figure, but may be present as shown in FIGS. 3-5.The male OUSB connector 88 comprises a plastic base or core 91. Thefemale OUSB connecter also comprises a plastic core 92 each surroundedby its own metal shield 93. The plastic cores 91 and 92 may includeV-grooves 95 to facilitate alignment of optical fibers 94 and 95.

After the plug (male) 90 and receptacle (female) 88 are mated, thelenses 43 and 80 are used to expanded the optical beam to facilitateoptical communication. As illustrated, the optical beam from the fiber94 from the male side may be expanded by lens 43 to, for example,approximately 1 mm. The expanded beam may then be collimated by theembedded lens 80 at the female side couple with fiber 95. Since theembedded lens profile 43 and 80 is identical at both sides, opticalsignals can go either direction. As one can see, expansion of the beammakes it possible to optically couple the fibers 94 and 95 sincetraditional butt coupling does not work well within the mechanicaltolerance confines of USB connectors.

While the above embodiments have been illustrated as USB “A” connectorsone skilled in the art will readily recognize that the inventiondescribed herein is equally applicable to USB “B” connectors or otherUSB form factors.

There are many advantages to OUSB. In particular, embodiments maintainall traditional USB electrical connections within the existing USB formfactor. Thus, it is fully backward compatibility with the USB 2.0specification. It allow super-high speed data rate (i.e. 10 Gbps)compared to the high speed of USB 2.0 (480 Mbps). In addition, opticalsignal integrity may be maintained in high EMI environments such asfactories where traditional electrical connections may experienceissues.

The above description of illustrated embodiments of the invention,including what is described in the Abstract, is not intended to beexhaustive or to limit the invention to the precise forms disclosed.While specific embodiments of, and examples for, the invention aredescribed herein for illustrative purposes, various equivalentmodifications are possible within the scope of the invention, as thoseskilled in the relevant art will recognize.

These modifications can be made to the invention in light of the abovedetailed description. The terms used in the following claims should notbe construed to limit the invention to the specific embodimentsdisclosed in the specification and the claims. Rather, the scope of theinvention is to be determined entirely by the following claims, whichare to be construed in accordance with established doctrines of claiminterpretation.

What is claimed is:
 1. A universal serial bus (USB) connector,comprising: an insulative base having a top surface and a leading edge;a plurality of pins on the top surface of the insulative base to makeelectrical connections; and at least one embedded lens on the leadingedge of the insulative base to provide optical function.
 2. The USBconnector as recited in claim 1, further comprising: at least one fiberoptically coupled to the at least one embedded lens.
 3. The USBconnector as recited in claim 2 wherein the embedded lens expands a beamemerging from the fiber.
 4. The USB connector as recited in claim 3wherein the embedded lens expands the beam to approximately 1 mm.
 5. TheUSB connector as recited in claim 2 wherein the embedded lens collimatesa beam into the fiber.
 6. The USB connector as recited in claim 2further comprising: four embedded lenses each respectively opticallycoupled to four fibers.
 7. The USB connector as recited in claim 1,further comprising: a mating connector comprising at least one embeddedlens to optically couple to the at least one embedded lens on theleading edge of the insulative base when mated.
 8. The USB connector asrecited in claim 7 wherein the embedded lens of the mating connector isidentical to the at least one embedded lens on the leading edge of theinsulative base.
 9. A method of providing optical function to a USBconnector, comprising: providing an insulative base having a top surfaceand a leading edge; positioning a plurality of pins on the top surfaceof the insulative base to make electrical connections; and embedding atleast one lens on the leading edge of the insulative base for opticalcommunication.
 10. The method as recited in claim 9 further comprising:expanding a beam emerging from a fiber with the embedded lens toapproximately 1 mm.
 11. The method as recited in claim 9, furthercomprising: collimating a beam onto a fiber with the embedded lens. 12.The method as recited in claim 9 further comprising: providing aplurality of embedded lenses on the leading edge of the insulative base.13. The method as recited in claim 9 further comprising: plugging theUSB connector into a mating connector to optically couple the embeddedlens to a corresponding lens in the mating connector.
 14. The method asrecited in claim 9 wherein the embedded lens and the corresponding lensin the mating connector are identical.
 15. An optical universal serialbus (OUSB), comprising: a universal serial bus (USB) connectorcomprising four electrical connections mounted to a top surface of aninsulative base; a plurality of embedded lenses on a leading edge of theinsulative base; a plurality of fibers each optically coupled to arespective one of the plurality of embedded lenses; wherein each lensexpands a beam traveling in a first direction from an optical fiber andcollimates a beam traveling in a second direction onto the optical fiberto meet USB mechanical tolerances.
 16. The OUSB as recited in claim 15wherein the OUSB is backward compatible with USB.
 17. The OUSB asrecited in claim 15 further comprising four embedded lenses on theleading edge of the insulative base.
 18. The OUSB as recited in claim 15further comprising: V-grooves in the insulative base to facilitatealignment of the fibers.
 19. The OUSB as recited in claim 15 furthercomprising; a mating OUSB connector having identical embedded lensesoptically aligned with the plurality of embedded lenses on a leadingedge of the insulative base when mated.
 20. The OUSB as recited in claim15 wherein the beam is expanded to approximately 1 mm.